Improvement in insulators for telegraph wires



D. BROOKS.

Insuiating Telegraph Wires.

Patented Marc'fi 26, 1867.

MPETERS, PHOTO-L THGGRAPHER wasmnsmu 0 C I @nitrh gums gaunt @ffim,

DAVID BROOKS, OF PHILADELPHIA, PENNSYLVANIA.

Letters Patent 1V0. 63,206, elated ilfarch 26, 1867.

IMPROVEMENT IN INSULATOBS FOR-TELEGRAPE WIRES,

@lge grlgttuh rennet ta it time fitters time amt muting not at flge time.

TO ALL WHOM IT MAY CONCERN:

Be known that I, DAVID BROoKS, of Philadelphia, Pennsylvania, have invented an Improvement in Insulating Telegraph Wires; and I dohereby declarethe following to be a full, clear, and exact description of the sa'me,'reference being had to the accompanying-drawing, and to the letters of reference marked thereon.

, My invention relates to that class of insulators which are so constructed that ah excessive charge of electricity thrown upon the wire will pass to an adjacent conductor without rupturing the material which insulates the wire-holder; and my invention consists of an arrangement of the parts of an insulator constructed in the manner fully described hereafter, whereby the above result is efiected. I

In order to enable others skilled in the art to apply my invention, I will now proceed to describe the man ner ofcarrying it into efiec t, reference being hadto the accompanying drawing, in'which Figure 1 is a view illustrating one mode of carrying out my improvement in insulating telegraph wires.

Figure'2, a sectional view, showing an insulated holder heretofore used, and

Figure 3 an inverted plan view of fig. '1.

.A, figs. 1 and 3, is a cylindrical metal case, which is secured firmly to-an arm, X, attached-to a telegraph pole or other suitable support. Within the case A is a block, 13, of dry Wood, glass, or other insulating material, in which is inserted-a wire-holder, O, the latter being insulated by a coating, a, of hard rubber, gutta percha, or other suitable material. If desired, a screw may be cut on the outside of the insulating coating a, so that the I holder may be secured in its place or detached with facility. At the lower end of the wire-holder are two curved arms or hooks 6 l the ends ofwhich areat such a distance from the lower edge of the case A that a wire, Y, may be passed between the two. A holder, consisting of a metal hook, O, (fig. 2,) with an insulated coating, a,

- has heretofore been used, the insulated end of the holder being screwed directly into the arm X of the pole or other support. It has been found that many of these holders gradually lose their insulating property and in a little while become worthless; as, when such holders are used, and when, by a stroke of lightning or from any other cause, the-wire becomes surcharged with electricity, the latter will escape from the wire or holder to the nearest conductorby the shortest passage, which is generally through the insulating coating 11- to the arm X, which, being wet, is a good conductor, the electricity in its passage through the coating perforating thc'latter, and the moisture passing into the said perforation and forming a conductor along. which the weaker currents, afterwards thrown on to the wire, escape to-the eartln This difiiculty has been heretofore overcome by so arranging the insulated wire-holder in respect to an exterior conductor that an excessive current thrown on to the wire will pass from the holder to the conductor without penetrating the insulating material. My invention is intended'merely to effect this object in an insulator of the construction above described, and illustrated in figs. 1 and?) of the drawing, thedifficulty being overcome by so adjusting the ease A'and the holder that the distancefrom any part of the latter through the insulating materials a and B to the nearest conductor is greater thanthe distance between the books I) Z; and the caseA. When, therefore, the wire is surcharged with electricity, there will be no inducement for the latter topenetrate the insulating coating (1 or wooden block B, as it can much more readilypass from the hooks b to the casing A.

I do not claim broadly the arrangement in an insulator of any description, of a conductor adjacent to a wire-holder for the purpose of conducting from the wire excessive charges of electricity, and thus preventing their passage through the insulating material; but I claim as my invention, and desire to secure by Letters Patent I I The metal casing A, insulating block B, and stem C, arranged and constructed as described, when the same are combined with arms or holders 6 b, so arranged that the distance between the holders and the case is less than that between the stem and case.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

DAVID BROOKS.

Witnesses:

CHARLES E. Fosrnn, W. J. R, DELANY. 

